Introduce "Wrapped IP" Token

[kingster-will]

Summary

This PR introduces the "Wrapped IP" (WIP) token, which is based on the WETH9 and WETH9.1 implementations. The WIP token includes support for the permit (ERC-2612) and permit2 functionalities, allowing for gas-efficient approvals.

Features

• ERC-20 Compliance: The WIP token adheres to the ERC-20 standard, ensuring compatibility with existing DeFi protocols and wallets.
• Permit (ERC-2612): Allows for gasless approvals by signing messages off-chain.
• Permit2: An enhanced version of the permit function for additional flexibility and security.
• Deposit Function: Users can deposit IP tokens (gas tokens) and receive an equivalent amount of WIP tokens.
• Withdrawal Function: Users can burn WIP tokens to receive the equivalent amount of IP tokens.

Implementation Details

• Contract: The WIP contract is implemented in src/WIP.sol.
• Deployment Script: A deployment script is provided in script/Deploy.s.sol to facilitate the deployment of the WIP contract.

Usage

1. Deposit IP Tokens: Call the deposit function to convert IP tokens to WIP tokens.
2. Withdraw IP Tokens: Call the withdraw function to convert WIP tokens back to IP tokens.
3. Permit: Use the permit function to approve token transfers via off-chain signatures.
4. Permit2: Use the permit2 function for enhanced approval mechanisms.

References

• WETH9 Implementation

Example

// Example of depositing IP tokens and receiving WIP tokens
wip.deposit{value: 1 ether}();

Notes

• This implementation prevents sending WIP tokens to the zero address or the contract itself.
• The permit and permit2 functions enhance user experience by reducing the need for on-chain approval transactions.